<template>
<div>
  <router-link to="/" tag='div' class="header-abs" v-show="showAbs">
    <div class="header-abs-back iconfont">&#xe624;</div>
  </router-link>
  <div class="header-fixed"  v-show='!showAbs' :style="opacityStyle">
    <router-link to="/">
      <div class="iconfont header-fixed-back">&#xe624;</div>
    </router-link>
    景点详情
  </div>
</div>
</template>

<script>
export default {
  name: 'DetailHeader',
  data () {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    }
  },
  methods: {
    handleScroll () {
      let top
      if (document.documentElement.scrollTop) {
        top = document.documentElement.scrollTop
      } else {
        top = document.body.scrollTop
      }
      // console.log(top)
      if (top > 60) {
        let opacity = top / 140
        opacity = opacity > 1 ? 1 : opacity
        this.opacityStyle = {
          opacity
        }
        this.showAbs = false
      } else {
        this.showAbs = true
      }
    }
  },
  activated () {
    window.addEventListener('scroll', this.handleScroll)
  },
  deactivated () {
    window.removeEventListener('scroll', this.handleScroll)
  }
}
</script>

<style scoped lang="stylus">
  @import '~styles/varibles.styl'
  .header-abs
    position: absolute
    border-radius .4rem
    background: rgba(0,0,0, .8)
    left: .2rem
    top: .2rem
    width: .8rem
    text-align center
    line-height .8rem
    height: .8rem
    .header-abs-back
      color: #fff
      font-size: .4rem
  .header-fixed
    z-index: 2
    position fixed
    top 0
    left 0
    right 0
    overflow: hidden
    height: .86rem
    line-height: .86rem
    text-align center
    background $bgColor
    color: #fff
    .header-fixed-back
      width: .64rem
      position absolute
      top 0
      left 0
      color #fff
      text-align center
      font-size: .4rem
</style>
